1. Our racial and cultural differences enhanced our relationship and taught us a great deal about tolerance, compromise, and being open with each other.
    我们之间的种族及文化差异不但增强了我们的关系，还教会了我们彼此间要宽容、谅解和开诚布公。

2. Which was greatly enhanced by the invention of printing.
    印刷术的发明又大大提高了知识增长的速度。